A certain page causes Page Settings to crash when I click it, giving the following error:

Error: is currently unavailable. DotNetNuke.Services.Exceptions.ModuleLoadException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object. at Dnn.Modules.Tabs.ManageTabs.SetValue(Control control, Hashtable tabSettings, String tabSettingsKey) at Dnn.Modules.Tabs.ManageTabs.BindTabControls(TabInfo tab) at Dnn.Modules.Tabs.ManageTabs.BindTab() at Dnn.Modules.Tabs.ManageTabs.OnLoad(EventArgs e) --- End of inner exception stack trace ---

Does anyone know why clicking Page Settings, in edit mode, would cause a crash?